TEDDY

The Environmental Determinants of Diabetes in the Young

The TEDDY study focuses on studying the role of environmental factors among children who are genetically susceptible to develop T1D. Several environmental factors are incriminated in the etiology of T1D such as gestational and childhood viral infections to such as changes in the gestational environment and infancy feeding, exposure to toxic substances in addition psychosocial problems. Since genetic risk factors in T1D are necessary but not sufficient to develop T1D; the role of environmental factors as “triggering” or “promoting” factors of autoimmune response is important. Understanding what environmental factors play a critical role in autoimmune response of T1D and the gene-gene and gene-environment interactions may produce valuable knowledge concerning the natural history and the etiology of T1D. Previous evidences were compromised by the presence of confounding factors such as recall bias and problems in accurately and early assessing genetic susceptibility and environmental exposures and a considerably large group of children.

The TEDDY study has an international setting and the study is implemented in six main research centers in the US (three centers) and Europe (Finland, Germany and Sweden). Participants are recruited from the general population and those who have at least one first-degree relative with T1D. Genetically susceptible children are recruited before or shortly after birth (based on family history and/or genetic analyses) where specimens are collected from the child as well as the parents. Infants with high genetic risk will be selected for detailed and long follow up for a variety of environmental factors such as history of infections and vaccinations, infancy and childhood nutrition and psychosocial problems. The participants will be followed until the age of 15 and blood sampling will be collected every three months for islet autoantibody measurements until age 4 years and then every six months afterwards.

The TEDDY study aims at recruiting a total of 7,801 participants out of around 35,000 newborn children who will be screened across six clinical centers worldwide (Finland, Germany, Sweden and three in North America). Out of those 788 neonates with first degree relatives who have type 1 diabetes and who have a pre-determined type 1 diabetes risk of 10%. The remaining 7,013 neonates will be recruited from the general population with a pre-determined type 1 diabetes risk of 3%.

The long-term goal of the TEDDY study is the identification of infectious agents, dietary factors, or other environmental agents, including psychosocial factors which trigger T1DM in genetically susceptible individuals or which protect against the disease. Identification of such factors will lead to a better understanding of disease pathogenesis and result in new strategies to prevent, delay or reverse T1DM.

TEDDY is supported by the National Institutes of Health specifically by the National Institute of Diabetes and Kidney Disease (NIDDK), National Institute of Infectious and Autoimmune Diseases (NIAID) and the Juvenile Diabetes Research Foundation.